Numerous heat exchangers of this type are already known, in which a first fluid, which is usually water, flows into one of the headers, after which it passes through the tubes of the bundle so as to reach the other header and eventually leave the heat exchanger, after having undergone heat transfer with another fluid, which is commonly an air stream directed over the tubes of the bundle. Such heat exchangers are mainly used as air/water heat exchangers: they find many varied applications in the automotive industry, especially for engine cooling purposes or for supplying heated air to the cabin of the vehicle.
However, heat exchangers of this type have not in the past been able to be used, having regard to the high temperatures employed, for the treatment of a high temperature air stream, for example in cooling of an air stream produced by the turbo compressor of an automotive or industrial vehicle. In this connection, the air stream delivered from a turbo compressor has a high temperature which is generally of the order of 250.degree. C., which has to be reduced to a temperature of the order of 100.degree. C. by heat transfer with the cooling water or cooling air.
In this particular application to cooling of the air stream delivered from a turbo compressor, a particular type of heat exchanger has been used up to the present time. This comprises two fluid headers, a multiplicity of spacing bars arranged in pairs, and a multiplicity of plates which are arranged in pairs so as to enclose the pairs of bars and to define, with the latter, fluid flow channels. One heat exchanger of this type is known in particular from the specification of French patent No. 80 06704, published under the number 2 479 438.
The main disadvantage of this type of heat exchanger lies in the complexity of the assembly of its various components.